1. Field of the Invention
The present invention provides a method for adjusting tray-in/out speeds of a tray, and more particularly, a method of determining an optimal control profile for adjusting tray-in/out speeds of a tray in an optical disk drive.
2. Description of the Prior Art
Tray-in/out speeds of a tray in a prior art optical disk drive are constant. The prior art optical disk drive controls the tray-in/out speeds with a direct-current motor by means of an open-loop-control method. The open-loop-control method includes operations of constant voltage/current, constant control profile, etc.
The open-loop-control method is to provide tray-in/out forces for the tray according to operations of the optical disk drive.
However, considering the cost of production, the prior art optical disk drive includes merely a limit switch instead of close-loop sensors for detecting whether the tray arrives at its end-stop.
In mass production, owing to: (1) different tray-in/out forces due to variations in disk clampers, (2) inconsistency of devices with different friction forces, and (3) different ways of oil filling with different brake forces, an unique and constant control profile is not suitable for all optical disk drives.
Furthermore, improper tray-in/out speeds can cause the tray to be incapable of driving all the way to its end-stop, or to accelerate rapidly, causing an optical disk to be out of position (i.e. dropped out from the tray) with excessive force. Therefore, to prevent the above-mentioned problem, a method for control tray-in/out speeds of a tray is expected.